Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share (ABOS)

Q: What does CUSIP 00509G209 represent in this 13F holders report?

CUSIP 00509G209 is the security identifier for ABOS - Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share used to aggregate holder disclosures.

Q: How many institutions held ABOS - Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share in Q1 2026?

84 institutional investors reported ABOS - Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share for Q1 2026. Use the holders table for investor-level position and value details.

CUSIP: 00509G209

Q1 2026 13F Holders as of 31 Mar 2026

Security type / class: Equity / Common Stock, $0.0001 par value per share
Total 13F shares: 46,001,051
Total 13F value: $108,541,469
Share change: +10,282,919
Put/Call ratio: 109%
SEC-reported price per share: $2.36
Number of holders: 84
Value change: +$24,478,369
Number of buys: 50
Number of sells: 17
Shares outstanding: 72,227,200

Security key

00509G209

Report period

Q1 2026

Institutions

Top holders

ABOS full security history Ownership snapshot Full 13F holder table Newer quarter: Q2 2026 Acumen Pharmaceuticals, Inc. SEC filings Acumen Pharmaceuticals, Inc. company facts

Broader feeds

Latest 13F filings Latest 13D/G filings Investors directory

Reporting periods

Holder history for CUSIP 00509G209

Newer quarter: Q2 2026

Recent filing periods:

Q2 2026

Ownership snapshot

Top reported holders of ABOS - Acumen Pharmaceuticals, Inc. - Common Stock, $0.0001 par value per share (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader

RA CAPITAL MANAGEMENT, L.P.

Disclosed value leader

RA CAPITAL MANAGEMENT, L.P.

Comparable rows

15/15

Latest evidence

13 Mar 2026

13D/G 13F Lead comparable stake: 30% 13D/G row: RA CAPITAL MANAGEMENT, L.P. Showing 1-6 of 15 holder rows.

Quick read

RA CAPITAL MANAGEMENT, L.P. leads the comparable SEC ownership view at 30%.

15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens RA CAPITAL MANAGEMENT, L.P.'s linked filing trail.

Comparable ownership Top 5

RA CAPITAL MANAGEMENT, L.P. 30%

Sands Capital Alternatives, LLC 5.6%

James B. Murray Jr. 5%

FRANKLIN RESOURCES INC 3.8%

FMR LLC 2.8%

Ownership % is shown only when SEC disclosures are safely comparable across share classes.

Detailed SEC evidence table Showing 1-6 of 15 holder rows

Holder	Evidence	Ownership %	Position	12M Net Δ	As of
RA CAPITAL MANAGEMENT, L.P.	13D/G 13F Company 13D/G 13F	30%	$55,075,356 21,101,669 shares	+$15,883,432	13 Mar 2026
Sands Capital Alternatives, LLC	13F 13D/G Company 13F 13D/G	5.6% from 13D/G	$7,210,028 3,417,075 shares	—	31 Dec 2025
James B. Murray Jr.	13D/G 13D/G	5%	$9,425,650 3,611,360 shares	$0	04 Apr 2025
FRANKLIN RESOURCES INC	13F 13D/G Company 13F 13D/G	3.8% from 13D/G	$4,863,753 2,305,096 shares	—	31 Dec 2025
FMR LLC	13F Company 13F	2.8%	$4,278,019 2,027,497 shares	—	31 Dec 2025
VANGUARD GROUP INC	13F Company 13F	2.3%	$3,489,459 1,653,772 shares	—	31 Dec 2025

How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

13F holder rows

Institutional holders as of Q1 2026

Investor-level positions for this CUSIP, loaded as an interactive table.

Institutions

46,001,051

Rows available

Investor	Option	Weight %	Change %	SEC-reported value	* Price	Shares	Share Change	Activity	Report Period

^* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.

Compare Q1 2026 vs Q1 2026 Across Filers

Q1 2026 holders

Holder diff

Investor	Q1 2026 Shares	Q1 2026 Shares	Share Diff	Share Chg %	Q1 2026 value	Q1 2026 value	Value change	Value Chg %

Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).

Quarterly Holders Trend

Quarterly Value Trend

Quarterly Shares Trend